Organic geochemistry of the Boltysh impact crater, Ukraine

The Boltysh crater has been know for several decades and was originally drilled in the 1960s - 1980s in a study of economic oil shale deposits. Unfortunately, the cores were not curated and have been lost. However we have recently re-drilled the impact crater and have recovered a near continuous record of ~400m of organic rich sediments deposited in a deep isolated lake which overly the basement rocks spanning a period ~10 Ma. The Boltysh impact crater, centred at 48°54–N and 32°15–E is a complex impact structure formed on the basement rocks of the Ukrainian shield. The age of the impact is 65.17±0.64 Ma [1]. At 24km diameter, the impact is unlikely to have contributed substantially to the worldwide devastation at the end of the Cretaceous. However, the precise age of the Boltysh impact relative to the Chicxulub impact and its location on a stable low lying coastal plain which allowed formation of the postimpact crater lake make it a particularly important locality. After the impact, the crater quickly filled with water, and the crater lake received sediment input from the surrounding land surface for a period >10 Ma [2]. These strata contain a valuable record of Paleogene environmental change in central Europe, and one of very few terrestrial records of the KT event. This preeminent record of the Paleogene of central Europe can help us to answer several related scientific questions. What is the relative age of Boltysh compared with Chicxulub? How long was the hydrothermal system active for after the impact event? How did the devastated area surrounding the crater recover, and how rapid was the recovery? The first sediments to be deposited in the crater lake were a series of relatively thin turbidites, the sediments then become organic rich shales and oil shales. Within the core there is ~400 m of organic rich shales/oil shales spanning a period of ~10 Ma some of which contain macrofossils such as ostracods, fish and plant fossils. Preliminary palynological studies suggest initial sedimentation was slow after the impact followed by more rapid sedimentation through the Late Paleocene. Hydrocarbons extracted from these samples are commonly dominated by terrestrial n-alkanes (Fig 1), Hopanes (including 3-methylhopanes) and steranes are also abundant and indicate the immaturity of the samples. The immaturity of samples is also evident from the abundance of hopenes, sterenes and oleanenes especially in the upper section of the core. In some of the oil shales the hopenes and sterenes are the most abundant hydrocarbons present. There is variation in the distribution of hydrocarbons/biomarkers and palynology throughout the core caused by changing inputs and environmental conditions

Gravitational wave energy spectrum of a parabolic encounter

We derive an analytic expression for the energy spectrum of gravitational waves from a parabolic Keplerian binary by taking the limit of the Peters and Matthews spectrum for eccentric orbits. This demonstrates that the location of the peak of the energy spectrum depends primarily on the orbital periapse rather than the eccentricity. We compare this weak-field result to strong-field calculations and find it is reasonably accurate (~10%) provided that the azimuthal and radial orbital frequencies do not differ by more than ~10%. For equatorial orbits in the Kerr spacetime, this corresponds to periapse radii of rp > 20M. These results can be used to model radiation bursts from compact objects on highly eccentric orbits about massive black holes in the local Universe, which could be detected by LISA.Comment: 5 pages, 3 figures. Minor changes to match published version; figure 1 corrected; references adde

A Catalog of Recombination Lines from 100 GHz to 10 Microns

We have made accurate calculations of recombination lines of H, He, C, and S from 100 GHz to 10 ?m (30 THz) that are useful to radio astronomers working at high frequencies. In particular, the fine structure of hydrogen has been treated explicitly for the First time in this radio-astronomical context

Blood tests in primary care:a qualitative study of communication and decision making between doctors and patients

OBJECTIVE: Blood tests are commonly used in primary care as a tool to aid diagnosis, and to offer reassurance and validation for patients. If doctors and patients do not have a shared understanding of the reasons for testing and the meaning of results, these aims may not be fulfilled. Shared decision‐making is widely advocated; yet, most research focusses on treatment decisions rather than diagnostic decisions. The aim of this study was to explore communication and decision‐making around diagnostic blood tests in primary care. METHODS: Qualitative interviews were undertaken with patients and clinicians in UK primary care. Patients were interviewed at the time of blood testing, with a follow‐up interview after they received test results. Interviews with clinicians who requested the tests provided paired data to compare clinicians' and patients' expectations, experiences and understandings of tests. Interviews were analysed thematically using inductive and deductive coding. RESULTS: A total of 80 interviews with 28 patients and 19 doctors were completed. We identified a mismatch in expectations and understanding of tests, which led to downstream consequences including frustration, anxiety and uncertainty for patients. There was no evidence of shared decision‐making in consultations preceding the decision to test. Doctors adopted a paternalistic approach, believing that they were protecting patients from anxiety. CONCLUSION: Patients were not able to develop informed preferences and did not perceive that choice is possible in decisions about testing, because they did not have sufficient information and a shared understanding of tests. A lack of shared understanding at the point of decision‐making led to downstream consequences when test results did not fulfil patients' expectations. Although shared decision‐making is recommended as best practice, it does not reflect the reality of doctors' and patients' accounts of testing; a broader model of shared understanding seems to be more relevant to the complexity of primary care diagnosis. PATIENT OR PUBLIC CONTRIBUTION: A patient and public involvement group comprising five participants with lived experience of blood testing in primary care met regularly during the study. They contributed to the development of the research objectives, planning recruitment methods, reviewing patient information leaflets and topic guides and also contributed to discussion of emerging themes at an early stage in the analysis process

Land clearing in Queensland triples after policy ping pong

[Extract] In 2013, a group of 26 senior scientists in Queensland (including ourselves) expressed serious concern that proposed changes to vegetation protection laws would mean a return to large-scale land clearing. The loss of these protections followed a Ministerial announcement in early 2012 that investigations into and prosecutions of illegal clearing would be halted

The effects of social service contact on teenagers in England

Objective: This study investigated outcomes of social service contact during teenage years. Method: Secondary analysis was conducted of the Longitudinal Survey of Young People in England (N = 15,770), using data on reported contact with social services resulting from teenagers’ behavior. Outcomes considered were educational achievement and aspiration, mental health, and locus of control. Inverse-probability-weighted regression adjustment was used to estimate the effect of social service contact. Results: There was no significant difference between those who received social service contact and those who did not for mental health outcome or aspiration to apply to university. Those with contact had lower odds of achieving good exam results or of being confident in university acceptance if sought. Results for locus of control were mixed. Conclusions: Attention is needed to the role of social services in supporting the education of young people in difficulty. Further research is needed on the outcomes of social services contact

ReconFusion: 3D Reconstruction with Diffusion Priors

3D reconstruction methods such as Neural Radiance Fields (NeRFs) excel at rendering photorealistic novel views of complex scenes. However, recovering a high-quality NeRF typically requires tens to hundreds of input images, resulting in a time-consuming capture process. We present ReconFusion to reconstruct real-world scenes using only a few photos. Our approach leverages a diffusion prior for novel view synthesis, trained on synthetic and multiview datasets, which regularizes a NeRF-based 3D reconstruction pipeline at novel camera poses beyond those captured by the set of input images. Our method synthesizes realistic geometry and texture in underconstrained regions while preserving the appearance of observed regions. We perform an extensive evaluation across various real-world datasets, including forward-facing and 360-degree scenes, demonstrating significant performance improvements over previous few-view NeRF reconstruction approaches.Comment: Project page: https://reconfusion.github.io

FIGS -- Faint Infrared Grism Survey: Description and Data Reduction

The Faint Infrared Grism Survey (FIGS) is a deep Hubble Space Telescope (HST) WFC3/IR (Wide Field Camera 3 Infrared) slitless spectroscopic survey of four deep fields. Two fields are located in the Great Observatories Origins Deep Survey-North (GOODS-N) area and two fields are located in the Great Observatories Origins Deep Survey-South (GOODS-S) area. One of the southern fields selected is the Hubble Ultra Deep Field. Each of these four fields were observed using the WFC3/G102 grism (0.8$\mu m$-1.15$\mu m$ continuous coverage) with a total exposure time of 40 orbits (~ 100 kilo-seconds) per field. This reaches a 3 sigma continuum depth of ~26 AB magnitudes and probes emission lines to $\approx 10^{-17}\ erg\ s^{-1} \ cm^{-2}$. This paper details the four FIGS fields and the overall observational strategy of the project. A detailed description of the Simulation Based Extraction (SBE) method used to extract and combine over 10000 spectra of over 2000 distinct sources brighter than m_F105W=26.5 mag is provided. High fidelity simulations of the observations is shown to significantly improve the background subtraction process, the spectral contamination estimates, and the final flux calibration. This allows for the combination of multiple spectra to produce a final high quality, deep, 1D-spectra for each object in the survey.Comment: 21 Pages. 17 Figures. To appear in Ap